<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link href="https://cdn.staticfile.org/twitter-bootstrap/5.1.1/css/bootstrap.min.css" rel="stylesheet">
    <script src="https://cdn.staticfile.org/twitter-bootstrap/5.1.1/js/bootstrap.bundle.min.js"></script>
</head>
<body>
hello
<ul class="dropdown-menu">
  <li><h6 class="dropdown-header">Dropdown header</h6></li>
  <li><a class="dropdown-item" href="#">Action</a></li>
  <li><a class="dropdown-item" href="#">Another action</a></li>
</ul>
</body>
</html>